the scope of the disaster in japan is becoming clearer each day. the death toll continuing to rise and survivors are cut off from rescuers and aid. 686 known dead. government officials say it will be much higher. an explosion today blew the roof and walls off a nuclear reactor. nine people exposed to radiation. four trains have disappeared and not been located and 9500 people in one coastal town have not been accounted for. the tsunami went as far as six miles inland. more strong aftershocks today in japan, largest magnitude 6.1 this morning. and that's prompting new concerns at the country's nuclear reactors. charlie d'agata with what is calling this anxiety. >> reporter: raising anxiety across japan. a cloud of white smoke cover thed nuclear complex after the blast. 170,000 people have been evacuated, 12 miles around the area. engineers are trying to get a handle on it and say the explosion destroyed the building that housed the reactor but not the reactor itself. the safety agency is reporting another emergency at a second reactor in the same co